← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 680 · 40 questions
TalentJR

The trick (Digits add to the 9 table): Add the digits you can see. Find the next number in the 9 table (9, 18, 27 …) above that total. The hidden digit is the difference. (Any number minus its digit sum is in the 9 table too.)

NameDateTime takenScore ___ / 40
  1. 1.?916 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 62 and take away the sum of its digits. What do you get?
  3. 3.Take 82 and take away the sum of its digits. What do you get?
  4. 4.Take 56 and take away the sum of its digits. What do you get?
  5. 5.257? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 84 and take away the sum of its digits. What do you get?
  7. 7.?924 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 11 and take away the sum of its digits. What do you get?
  9. 9.4?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.9?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.770? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 34 and take away the sum of its digits. What do you get?
  13. 13.Take 73 and take away the sum of its digits. What do you get?
  14. 14.Take 41 and take away the sum of its digits. What do you get?
  15. 15.120? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.832? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 35 and take away the sum of its digits. What do you get?
  18. 18.Take 57 and take away the sum of its digits. What do you get?
  19. 19.Take 20 and take away the sum of its digits. What do you get?
  20. 20.Take 60 and take away the sum of its digits. What do you get?
  21. 21.?277 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 31 and take away the sum of its digits. What do you get?
  24. 24.Take 29 and take away the sum of its digits. What do you get?
  25. 25.2?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.675? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 39 and take away the sum of its digits. What do you get?
  28. 28.3?31 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?295 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?929 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.305? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 50 and take away the sum of its digits. What do you get?
  33. 33.7?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.492? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?421 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.510? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?568 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.341? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 89 and take away the sum of its digits. What do you get?
  40. 40.86?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 2
  2. 54
  3. 72
  4. 45
  5. 4
  6. 72
  7. 3
  8. 9
  9. 2
  10. 6
  11. 4
  12. 27
  13. 63
  14. 36
  15. 6
  16. 5
  17. 27
  18. 45
  19. 18
  20. 54
  21. 2
  22. 4
  23. 27
  24. 18
  25. 2
  26. 9
  27. 27
  28. 2
  29. 2
  30. 7
  31. 1
  32. 45
  33. 9
  34. 3
  35. 2
  36. 3
  37. 8
  38. 1
  39. 72
  40. 1

Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks